REG101
REG
101
www.ti.com
DMOS
100mA Low-Dropout Regulator
FEATURES
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NEW DMOS TOPOLOGY:
Ultra Low Dropout Voltage:
60mV typ at 100mA
Output capacitor NOT required for stability
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FAST TRANSIENT RESPONSE
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VERY LOW NOISE: 23
µ
Vrms
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HIGH ACCURACY:
±
1.5% max
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HIGH EFFICIENCY:
I
GND
= 500
µ
A at I
OUT
= 100mA
Not Enabled: I
GND
= 10nA
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2.5V, 2.8V, 2.85V, 3.0V, 3.3V, 5.0V AND
ADJUSTABLE OUTPUT VERSIONS
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OTHER OUTPUT VOLTAGES AVAILABLE
UPON REQUEST
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FOLDBACK CURRENT LIMIT
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THERMAL PROTECTION
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SMALL SURFACE-MOUNT PACKAGES:
SOT23-5 and SO-8
DESCRIPTION
The REG101 is a family of low noise, low dropout
linear regulators with low ground pin current. Its new
DMOS topology provides significant improvement
over previous designs, including low dropout voltage
(only 60mV typ at full load), and better transient
performance. In addition, no output capacitor is re-
quired for stability, unlike conventional low dropout
regulators that are difficult to compensate and require
expensive low ESR capacitors greater than 1µF.
Typical ground pin current is only 500µA (at I
OUT
=
100mA) and drops to 10nA when not enabled mode.
Unlike regulators with PNP pass devices, quiescent
current remains relatively constant over load variation
and under dropout conditions.
The REG101 has very low output noise (typically
23µVrms for V
OUT
= 3.3V with C
NR
= 0.01µF),
making it ideal for use in portable communications
equipment. Accuracy is maintained over temperature,
line, and load variations. Key parameters are guaran-
teed over the specified temperature range
(–40°C to +85°C).
The REG101 is well protected—internal circuitry pro-
vides a current limit which protects the load from
damage. Thermal protection circuitry keeps the chip
from being damaged by excessive temperature. The
REG101 is available in the SOT23-5 and the SO-8
packages.
APPLICATIONS
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PORTABLE COMMUNICATION DEVICES
BATTERY-POWERED EQUIPMENT
PERSONAL DIGITAL ASSISTANTS
MODEMS
BAR-CODE SCANNERS
BACKUP POWER SUPPLIES
Enable
V
IN
+
0.1µF
REG101
(Fixed Voltage
Versions)
Gnd
+
V
OUT
C
OUT(1)
V
IN
Enable
V
OUT
+
0.1µF
REG101-A
R
1
Adj
Gnd
NOTE: (1) Optional.
R
2
+
C
OUT(1)
NR
NR = Noise Reduction
Copyright © 2000, Texas Instruments Incorporated
SBVS026B
Printed in U.S.A. February, 2001
ETC [ ETC ]
